To function properly at altitude, where air pressure has a low density, internal combustion engines on board vehicles, such as aircraft, use cooling air to condition intake air for proper engine function. Such engines use a compressor to increase the mass of flow rate of air to the engine intake. Because a compressor increases the temperature of the charge air, the engine intake also includes an intercooler or heat exchanger to cool the compressed air. Further, such engines may include one or more radiators to dissipate engine heat during operation.
However, if an intercooler undercools the charge air to an engine, such undercooled air can adversely affect the performance of the engine. Conversely, if the operation of the intercooler rejects excessive amounts of heat into the cooling air stream, the radiator would need to be oversized due to the warmer cooling air steam or, and hence the engine, may be adversely affected. In addition, such engines need to be capable of operation at low altitude or ground, where the aircraft is moving at a relatively low velocity, or is stationary. Accordingly, there is a need for a compact engine cooling system for an aircraft that utilizes minimally sized components despite the potential for divergent thermal rejection requirements that would have different optimal configurations for altitude and on ground.